Developer Guide

This section is for anyone working on TrangoPlayer's own source code, rather than just using the app. It covers how the codebase is put together, why specific implementation decisions were made, and the third-party libraries it depends on.

A few other documents outside this book are worth knowing about:

• The repository root SPEC.md is the original product handoff spec — views, states, and interactions. STYLE.md holds the accompanying visual design reference and design tokens.
• CLAUDE.md covers the development workflow: TDD, the scripts/ helpers, git workflow, and Rust conventions used throughout the codebase.
• TODO.md is the step-by-step development roadmap the project was built against.

In this section

• Architecture — crate structure, the state model, and how video playback is embedded in the UI.
• Design decisions — a running log of implementation decisions and the bugs/tradeoffs that shaped them, for behavior not already covered by the handoff spec.
• Technology choices — one page per notable dependency: why it was chosen and how it's used here.